JP2002172791A - Method for manufacturing piezoelectric element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of making a piezoelectric element wherein widths of electrodes can be made equal. SOLUTION: When the electrodes 24 and the like are to be printed by screen printing, firstly preliminary printing is executed, and an irregular distribution in widths of electrode patterns in the printed position is measured. A width of a hole section corresponding to the electrode pattern in a printing plate is corrected so as to eliminate the irregular distribution based on the measured result, and then the printing of the electrodes is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the technical field of a method of manufacturing a piezoelectric element in a piezoelectric ink jet printer head.

[0002]

2. Description of the Related Art In an ink jet printer head used in an ink jet printer, a piezoelectric element provided adjacent to a pressure chamber in a cavity is used, and a voltage is applied to the piezoelectric element to reduce the volume of the pressure chamber. 2. Description of the Related Art A piezoelectric ink jet printer head that performs printing by ejecting ink from an orifice is known.

In this piezoelectric ink jet printer head, an internal electrode layer is printed by screen printing on a sheet-like piezoelectric ceramic layer, and each piezoelectric ceramic layer and a ceramic layer having no electrode layer are alternately laminated. Pressed and fired, fired, and then bonded with a deformation restricting material using a separate adhesive or the like.

[0004]

However, in the above-mentioned conventional method for manufacturing a piezoelectric element, in the electrode printing step by screen printing, there is a problem that printing bleeding, blurring, etc. occur, and the electrode width becomes non-uniform. there were.

In other words, since the electrode width varies depending on the location, the electrical characteristics of the piezoelectric elements corresponding to the respective pressure chambers vary, and the amount of deformation of the piezoelectric elements varies, so that uniform discharge characteristics cannot be obtained. . At the same time, when manufacturing piezoelectric elements for a plurality of ink jet printer heads, there is a problem that the ejection characteristics vary from head to head.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a method of manufacturing a piezoelectric element in which electrodes can be made equal in width.

[0007]

According to a first aspect of the present invention, there is provided a method of manufacturing a piezoelectric element, the method comprising the steps of: attaching a piezoelectric element to a cavity plate forming a pressure chamber; A method of manufacturing a piezoelectric element to be formed, comprising: forming a plate having a hole in accordance with an electrode pattern; trial printing an electrode forming member using the plate; and Measuring the non-uniform distribution of the electrode pattern width by, and, according to the measurement result, correcting the width of the hole so as to eliminate the non-uniformity,
Using the corrected plate making, a step of forming an electrode pattern on a sheet-shaped member made of a piezoelectric material, a step of stacking the sheet-shaped member on which the electrode pattern is formed, and the stacked sheet-shaped member, The method includes a step of placing the sheet-like member on the support member having a flat surface, and a step of sintering the sheet-like member placed above.

According to the method of manufacturing a piezoelectric element according to the first aspect, first, a plate making having a hole according to an electrode pattern is formed. Next, trial printing of the electrode forming member is performed using the plate making. After the test printing, the nonuniform distribution of the electrode pattern width depending on the printing position is measured, and the width of the hole is corrected according to the measurement result so as to eliminate the nonuniformity. Next, an electrode pattern is formed on a sheet-shaped member made of a piezoelectric material using the corrected plate making. Then, the sheet members on which the electrode patterns are formed are laminated, the laminated sheet members are placed on a support member having a flat surface, and the placed sheet members are sintered. . Thus, a piezoelectric element is manufactured. Therefore,
Since the holes of the plate making are corrected based on the non-uniform distribution actually measured as described above, in the manufactured piezoelectric element, each electrode pattern width becomes equal, and the width of each electrode pattern corresponds to each pressure chamber. The electrical characteristics of the piezoelectric element or the piezoelectric element for each head are uniform, and the displacement of the piezoelectric element is also uniform. As a result, a piezoelectric element having uniform ink ejection performance is provided.

According to a second aspect of the present invention, there is provided a method of manufacturing a piezoelectric element according to the first aspect of the present invention, wherein the plate is formed at a plurality of positions for one piezoelectric element. The hole groups are arranged in parallel at a plurality of locations for each piezoelectric element so that a plurality of piezoelectric elements are manufactured at one time, and the unevenness is eliminated. The hole correcting step is performed for each hole group, and further includes a step of separating each of the piezoelectric elements after the sintering.

According to the method of manufacturing a piezoelectric element according to the second aspect, the hole in the plate making is formed by:
It is provided in parallel at a plurality of places to form a hole group. Further, the hole group is provided in a plurality of places for each piezoelectric element so as to manufacture a plurality of piezoelectric elements at once. Then, the hole correcting process for eliminating the non-uniformity is performed for each hole group, and the plurality of piezoelectric elements manufactured at one time are separated for each piezoelectric element after the sintering. Therefore, even when a plurality of piezoelectric elements are manufactured at one time, the electrode width of each piezoelectric element can be made uniform.

According to a third aspect of the present invention, there is provided a method of manufacturing a piezoelectric element according to the first or second aspect, wherein each of the electrode pattern widths is equal to two.
The thickness is set to 50 μm or less.

According to the third aspect of the present invention, since the width of each electrode pattern is set to 250 μm or less, it is possible to manufacture a piezoelectric element having a very narrow pitch. However, when the electrode width is as small as 250 μm or less, the influence of the difference in the width of each electrode on the capacitance of each electrode increases. However, as described above, the electrode width becomes uniform. Even when the electrode width is small, the capacitance of each electrode is made uniform.

According to a fourth aspect of the present invention, in the method of manufacturing a piezoelectric element according to any one of the first to third aspects, the step of forming the electrode pattern is a step of using a screen printing method. It is characterized by the following.

According to the method of manufacturing a piezoelectric element of the present invention, since the electrode pattern is formed by using a screen printing method, a large number of electrode patterns can be easily formed at one time. Thus, the width of each electrode pattern is made uniform.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a piezoelectric element according to any one of the first to fourth aspects, wherein the electrode material forming the electrode pattern is Ag-Pd.

According to the method of manufacturing a piezoelectric element of the present invention, since the electrode pattern is formed of Ag-Pd, it can be easily formed even if the electrode pattern has a small width. And good electrical characteristics are obtained. However,
At the time of printing, there is a tendency to cause bleeding or blurring, but the electrode pattern width is formed uniformly through the test printing process as described above. Therefore, according to the present invention, an electrode pattern having a uniform width can be easily formed.

[0017]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. The following description is an embodiment in which the present invention is applied to a piezoelectric inkjet head.

As shown in FIG. 3, a main body frame 1 mounted on a known carriage (not shown) running along a recording medium is formed in a substantially box shape having an open top surface. A mounting portion 3 to which two ink cartridges (not shown) can be removably mounted, and an ink supply portion which can be connected to an ink discharging portion (not shown) of each ink cartridge is provided on one side portion 3a of the mounting portion 3 Passages 4a, 4b, 4
c and 4d communicate with the lower surface of the bottom plate 5 of the main body frame 1. In addition, on the upper surface of one side portion 3a of the mounting portion 3,
Packing (not shown) made of rubber or the like so that it can be in close contact with the ink discharge section (not shown) of each ink cartridge
Is arranged.

The bottom plate 5 is formed horizontally so as to protrude downward from the mounting portion 3 by one step.
As shown in FIG. 2, on the lower surface side of the bottom plate 5, two front head units 6, which will be described later, are arranged in parallel.
The two support parts 8 are formed in a stepped shape. Each support portion 8 has a plurality of cavities 9a and 9 for fixing with a UV adhesive.
b is formed so as to penetrate vertically.

FIG. 5 is a perspective view of the front head unit 6. FIG. 6 is a sectional view of the front head unit. Front head unit 6
As shown in FIGS. 5 and 6, a plurality of laminated cavity plates 10 and a plate-shaped piezoelectric actuator 20 adhered and laminated to the cavity plates 10 via an adhesive or an adhesive sheet are provided. A flexible flat cable 40 is formed on the upper surface of the lower surface of the cavity plate 10 by an adhesive so as to be electrically connected to an external device. Ink is ejected.

FIG. 7 is an exploded perspective view of the cavity plate 10. As shown in FIG. FIG. 8 shows the cavity plate 1
FIG. 2 is an exploded enlarged perspective view of FIG. As shown in FIG. 8, the cavity plate 10 includes a nozzle plate 11,
Two manifold plates 12 and spacer plate 1
3. A structure in which five thin metal plates of the pace plate 14 are overlapped and bonded with an adhesive, respectively. In this embodiment, each of these plates 11 to 14 is made of a 42% nickel alloy steel plate (42 alloy) and has a thickness of 50 μm to 150 μm.
About the same thickness. Each of these plates 1
1 to 14 are not limited to metal and may be formed of, for example, resin.

The nozzle plate 11 is provided with a plurality of nozzles 15 for discharging ink having a very small diameter (about 25 μm in the present embodiment) along the longitudinal center lines 11 a and 11 b of the nozzle plate 11 at a fine pitch. The holes are formed in a staggered arrangement at intervals of P. The structure is a hermetically sealed structure by laminating the nozzle plate 11 and the spacer plate 13 on the two manifold plates 12.

As shown in FIG. 8, a plurality of narrow pressure chambers 16 extending in a direction perpendicular to the longitudinal center lines 14a and 14b are formed in the base plate 14 in a staggered arrangement. I have. In addition, the base plate 14 includes
A throttle portion 16d connected to each pressure chamber 16 is provided. Further, an ink supply hole 16b connected to the throttle portion 16d is formed. Each of the ink supply holes 16b is connected to the manifold plate 12 via an ink supply hole 18 formed in both right and left portions of the spacer plate 13.
Are connected to the common pressure chamber 12a. Here, the cross-sectional area orthogonal to the direction in which the ink flows in each of the constricted portions 16 d is smaller than the cross-sectional area of each of the pressure chambers 16. This is because the flow path resistance is increased by reducing the cross-sectional area of the throttle section 16d.

One end 16a of each pressure chamber 16 has a small-diameter penetrating hole formed in the staggered arrangement of the nozzles 15 in the nozzle plate 11 in the spacer plate 13 and the two manifold plates 12 in a staggered arrangement. Hole 17
Through the nozzles 15 corresponding to the respective pressure chambers 16.

FIG. 9 is an exploded perspective view of the piezoelectric actuator 20. Piezoelectric actuator 20
Are three ceramic sheets 2 as shown in FIG.
1, 22, and 23 are laminated. A plurality of narrow drive electrodes 24 corresponding to each pressure chamber 16 in the cavity plate 10 are provided on the upper surface of the lowermost sheet 21.
They are provided in a staggered arrangement. One end 24 a of each drive electrode 24 is connected to the front and back surfaces 20 of the piezoelectric actuator 20.
It is formed so as to be exposed on left and right side surfaces 20c orthogonal to a and 20b.

On the upper surface of the next sheet 22, a common electrode 25 common to the plurality of pressure chambers 16 is provided. One end 25a of the common electrode 25 is also connected to each drive electrode 24.
Like the one end portion 24a, it is formed so as to be exposed on the left and right side surfaces 20c.

On the upper surface of the uppermost sheet 23, a surface electrode 26 for each of the drive electrodes 24 and a common electrode 25
Are provided so as to be arranged along the left and right side surfaces 20c.

The drive electrodes 2 are provided on the left and right side surfaces 20c.
4 is provided with a first recessed groove 30 at one end 24a of the common electrode 2.
The second recessed groove 31 is provided at one end 25a of the fifth member 5 so as to extend in the laminating direction. Each first concave groove 3
6, a side electrode 32 for electrically connecting each drive electrode 24 and each surface electrode 26 is provided, and a common electrode 25 and a surface electrode 27 are provided in the second concave groove 31, as shown in FIG. And side electrodes 33 for electrically connecting the electrodes to each other. The electrodes 28 and 29 are discarded pattern electrodes.

Each region of the sheet 22 sandwiched between the position corresponding to each drive electrode 24 and the common electrode 25 is subjected to polarization processing to impart piezoelectric characteristics, and becomes a pressure generating section corresponding to each pressure chamber 16.

The cavity plate 1 having the above configuration
0 and the piezoelectric actuator 20, each pressure chamber 16 in the cavity plate 10 and the piezoelectric actuator 20
Are laminated so as to correspond to the drive electrodes 24 in the above.
Also, the upper surface 20 of the piezoelectric actuator 20
Various wiring patterns (not shown) in the flexible flat cable 40 are electrically connected to the surface electrodes 26 and 27 by overlapping and pressing the flexible flat cable 40 on a.

In such a configuration, by applying a voltage between any of the drive electrodes 24 of the piezoelectric actuator 20 and the common electrode 25, the drive of the piezoelectric sheet 22 to which the voltage is applied is performed. Electrode 2
In the portion 4, that is, in the pressure generating portion, distortion in the stacking direction occurs due to the piezoelectric effect. Then, the internal volume of the pressure chamber 16 corresponding to each drive electrode 24 is reduced by the pressure due to the distortion, so that the ink in the pressure chamber 16 is ejected from the nozzle 15 in a droplet form, and Is printed.

Here, a method of manufacturing the piezoelectric actuator 20 will be described. First, ferroelectric lead zirconate titanate (PZT (PbTiO ₃ .PbZr
O ₃ )) A ceramic powder, a binder and a solvent are mixed.

Next, the mixed solution is applied to a predetermined thickness on a plastic film such as PET (polyethylene terephthalate) using a doctor blade method, and three green ceramic sheets 21, 22 and 23 are formed. Form a sheet. Each green sheet has a size corresponding to a plurality of piezoelectric actuators as shown in FIG.

Further, as shown in FIG. 10, Ag-
A metal material made of Pd is printed by screen printing.

Then, the green sheets thus formed are laminated and heated and pressed to obtain a laminated block of green sheets.

Next, the laminated block is heated at a predetermined temperature to burn off the binder, and then fired at a predetermined temperature in a firing furnace.

Then, the block is cut into a predetermined size to obtain individual piezoelectric actuators 20.

Next, the side electrodes 32, 33 are printed on the individual piezoelectric actuators 20, and the side electrodes 32, 33 are printed using a firing furnace.

Then, by applying a high voltage to the electrodes 24 and 25, the polarization treatment of the ceramic sheet 21 between both electrodes is performed.

As described above, the piezoelectric actuator 20 used in the piezoelectric ink jet head of the present embodiment is used.
Is manufactured.

According to the above manufacturing method, 250 μm
The piezoelectric actuator 20 having a fine electrode width of not more than m can be obtained.

In particular, in this embodiment, in the electrode printing process as described above, the width of the printing hole of the drive electrode 24 formed on the plate for screen printing is made non-uniform in the printing direction. As a result, the width of the drive electrodes after printing can be made equal. As a result, the amount of deformation in the piezoelectric actuator 20 is equal in each channel, and the piezoelectric actuator 20 having the same electrical characteristics in each channel can be manufactured. I can do it.

On the other hand, in the conventional manufacturing method,
Since the drive electrode printing holes formed in the plate making were all configured to have the same width, the electrode width varied depending on the location as shown in FIG.

FIG. 10 is a diagram showing the electrode width on the green sheet after the printing process of the drive electrode 24.

As shown in FIG. 10, a location number is printed on a ceramic green sheet for each portion corresponding to each piezoelectric actuator.

In the printing process of the drive electrode 24, ink is supplied onto the plate making in the same manner as in known screen printing, and coating is performed in one direction by a coating member.
The locations are set in the direction of location numbers 6 and 12 from location numbers 1 and 7 shown in FIG.

Therefore, when the widths of the holes of the plate making are all equal, when the ink is applied in the above-mentioned direction, the width of the electrode 24 of the location number 1 is larger than the width of the electrode 24 of the location number 6. On the contrary, the width of the electrode 24 of the location number 6 becomes narrower than the width of the electrode 24 of the location number 1. Thus, the electrode width was not uniform.

However, in this embodiment, the width of the plate making holes corresponding to the location numbers 1 and 7 is smaller than the width of the plate making holes corresponding to the location numbers 6 and 12. did.

Then, the width of the hole of the plate making corresponding to each location number is determined by performing trial printing once, examining the tendency of electrode width variation, and making the electrode widths after printing all equal. The size was set.

As a result, even in the printing process of the drive electrode 24, all electrode widths could be made equal. As a result, the electric characteristics of the piezoelectric actuator 20 became equal for each head or each pressure chamber, and the piezoelectric actuator 20 having the same ink discharge performance for each head or each pressure chamber could be manufactured.

In particular, in the present embodiment, the width of the electrode is as fine as 250 μm or less, preferably 150 μm.
The effect on the variation in capacitance is large. However,
As described above, according to the present embodiment, since all electrode widths are uniform, 250 μm or less, preferably 150 μm or less.
Even when a fine electrode of m is used, there is an extremely excellent effect that the capacitance of each electrode can be made uniform and the electrical characteristics of each electrode can be made uniform.

[0052]

According to the method of manufacturing a piezoelectric element according to the first aspect of the present invention, in the method of manufacturing a piezoelectric element which is adhered and attached to a cavity plate forming a pressure chamber and forms a head of an ink jet printer together with the cavity plate. Forming a plate having holes in accordance with the pattern, testing the electrode forming member using the plate, and measuring the non-uniform distribution of the electrode pattern width depending on the printing position after the test printing. And correcting the width of the hole so as to eliminate the non-uniformity according to the measurement result, and forming an electrode pattern on a sheet-shaped member made of a piezoelectric material using the corrected plate making. In this case, the width of each electrode pattern can be equalized in the manufactured piezoelectric element, and the electrical characteristics of each channel can be equalized. It can be made. Therefore, the amount of displacement of the piezoelectric element in each pressure chamber or each head becomes uniform, and a piezoelectric element with uniform ink ejection performance can be provided.

According to a second aspect of the present invention, in the plate making method, the holes are arranged in parallel at a plurality of locations for one piezoelectric element to form a group of holes, and a plurality of piezoelectric elements are formed. The hole groups are arranged in a plurality of positions for each piezoelectric element so as to be manufactured at one time, and the hole correcting step for eliminating the non-uniformity is performed for each hole group. After the sintering, the method further includes a step of separating each piezoelectric element, so that even when a plurality of piezoelectric elements are manufactured at once, the electrode width can be made uniform in each piezoelectric element.

According to the third aspect of the present invention, since the width of each electrode pattern is set to 250 μm or less, the electrode width is uniform, and the capacitance of each electrode is uniform. And a very narrow pitch piezoelectric element can be easily manufactured.

According to the method for manufacturing a piezoelectric element of the present invention, since the electrode pattern is formed by using a screen printing method, a large number of electrode patterns can be easily formed at one time. As described above, the width of each electrode pattern can be made uniform.

According to the fifth aspect of the present invention, since the electrode pattern is formed of Ag-Pd, an electrode pattern having a uniform width can be easily formed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a piezoelectric inkjet head according to an embodiment of the present invention, with the nozzle side facing upward.

FIG. 2 is an exploded perspective view of parts of the piezoelectric inkjet head of FIG.

FIG. 3 is an exploded perspective view of components of the piezoelectric inkjet head of FIG. 1 as viewed from above.

FIG. 4 is a bottom view of the bottom plate of the main body frame of the piezoelectric ink jet head of FIG. 1 as viewed from below.

FIG. 5 is a perspective view of a front head unit in the piezoelectric inkjet head of FIG. 1;

FIG. 6 is a cross-sectional view of a front head unit in the piezoelectric inkjet head of FIG.

FIG. 7 is an exploded perspective view of a cavity plate in the piezoelectric ink jet head of FIG.

8 is an exploded enlarged perspective view of a cavity plate in the piezoelectric ink jet head of FIG.

FIG. 9 is an exploded perspective view of a piezoelectric actuator in the piezoelectric ink jet head of FIG. 1;

FIG. 10 is a view showing an electrode width on a piezoelectric ceramic sheet after a conventional printing process.

[Explanation of symbols]

 Reference Signs List 20 piezoelectric actuator 21, 22 piezoelectric sheet 23 insulating sheet 24 drive electrode 25 common electrode 26, 27 surface electrode 30, 31 concave groove 32, 33 side electrode

Claims (5)

[Claims] 1. A method of manufacturing a piezoelectric element which is bonded and attached to a cavity plate forming a pressure chamber and forms a head of an ink jet printer together with the cavity plate, wherein a plate making having a hole is formed according to an electrode pattern. A step of test-printing the electrode forming member using the plate making; a step of measuring the non-uniform distribution of the electrode pattern width depending on a printing position after the test printing; and the non-uniform distribution according to the measurement result. Correcting the width of the hole so as to solve the problem, forming an electrode pattern on a sheet-shaped member made of a piezoelectric material using the corrected plate, and forming a sheet on which the electrode pattern is formed. A step of laminating a sheet-like member; a step of placing the laminated sheet-like member on a support member having a flat surface; Method for manufacturing a piezoelectric element characterized by comprising a step of sintering the timber, the. 2. The plate making method according to claim 1, wherein the holes are arranged in parallel at a plurality of positions for one piezoelectric element to form a hole group,
In order to manufacture a plurality of piezoelectric elements at one time, the hole group is provided in a plurality of places for each piezoelectric element, and the hole correcting step for eliminating the non-uniformity is performed by each hole group. 2. The method according to claim 1, further comprising a step of separating the piezoelectric elements after the sintering for each piezoelectric element. 3. The method according to claim 1, wherein the width of each electrode pattern is set to 250 μm or less.
The manufacturing method of the piezoelectric element according to the above. 4. The method for manufacturing a piezoelectric element according to claim 1, wherein the step of forming the electrode pattern is a step using a screen printing method. 5. The method according to claim 1, wherein an electrode material for forming the electrode pattern is Ag-Pd.